Stripe found 7.4% of sign-ups at AI companies were linked to multi-account abuse.
One person opens many free accounts, and each one uses up credits you pay for.
Block fake signups and follow up the real ones
One layer in your signup flow checks whether each new account is a real person, finds out who they are, and decides what happens next: their free credits, an extra check or a block, and a follow-up.
Fake accounts burn your free credits, and the real signups get no follow-up
Stripe saw abuse attempts at AI startups rise 40% between January and June 2026. Blocking the fakes and following up the real signups usually takes three to five separate tools today.
Verisoul reports that 47% of Clay’s sign-ups were fake or duplicates.
Fake and duplicate accounts burn free credits and throw off your signup numbers.
Three answers for every signup, then a watch on usage
Each new account gets a decision before it gets any free credits, built to arrive in under a second. After signup, Doorwise keeps an eye on how those credits are used.
Real?
jordan.k+trial4@gmail.com
Signed up at 09:41 from a datacenter IP
- What we found
- A Gmail variant of an account from last week, on the same device as 2 earlier signups
- Decision
- Extra check before any credits
Built to set up in minutes, without a sales call
One script on your signup page, plus ready-made connections to the login tools SaaS teams already use.
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Step 1
Add one script to your signup page.
- No sales call
- Runs on the signup page you already have
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Step 2
Connect your login tool.
- Supabase, Clerk or Auth0
- Firebase or Stripe
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Step 3
Set what happens to each kind of signup.
- Full credits, drip credits or card required
- An email in your voice, a Slack alert or nothing
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Every week
Get your report of dollars saved and leads found.
- Fast credit burners slowed down
- Real signups worth a follow-up
Every week: dollars saved and real leads found
Each signup’s trust score, identity and usage build up into your signup memory. The weekly report shows what was caught and who is worth a follow-up.
1,240signups checked
96fake or linked accounts
14real leads to follow up
Last week, $1,180 of free credits stayed away from fake accounts.
- Blocked
31 throwaway-email signups
Disposable domains and Gmail variants of existing accounts.
- Slowed
6 accounts burning credits fast
Linked by device to earlier trials. Their credits now drip.
- Lead
Head of Growth at a 40-person fintech
High fit. An email in your voice went out on day one.
- Lead
CTO at a Series A AI startup
High fit. Your team got a Slack alert.
How teams handle signups today, and where Doorwise fits
Block tools stop fake accounts, and identify tools research the real ones. Doorwise does both in one decision, then sets credits and follows up.
| Capability | Block toolsStripe Radar, Verisoul, Fingerprint, Castle, SEON | Identify toolsClay, Common Room, RB2B, Default | DoorwiseBoth, in one decision |
|---|---|---|---|
| Blocks fake and duplicate accounts | Approve, extra check or block, with the reason | ||
| Finds out who the person is | Role, company, size and fit score | ||
| Sets free credits by trust | Varies | Full credits, drip credits or card required | |
| Follows up the real signups | Varies | An email in your voice or a Slack alert | |
| Price | Fingerprint from $99 a month | Clay from $167 a month | Early access, price not set yet |
Start with a check of your last 30 days of signups.
We run Doorwise on your past month of signups and show what share was fake, how many free credits they burned, and which real signups are worth an email.
Who it’s for
- SaaS with a self-serve free trial or free plan
- Around 1,000 or more signups a month
- Seed to Series B, AI products especially
Questions about Doorwise
It sits in your signup flow and answers three questions about each new account: is this person real, who are they, and what should happen next. After signup it watches usage, and every week it sends you a report of dollars saved and real leads found.
Every decision comes with its reason, and you set the rules. A signup that looks unclear can get an extra check or drip credits instead of a block.
It’s built to answer in under a second, so a new user isn’t left waiting.
Supabase, Clerk, Auth0, Firebase and Stripe, plus one script on your signup page. The aim is setup in minutes, with no sales call.
Person and company lookups through data APIs, plus a short AI research summary. You get their role, company, company size and a fit score.
They cover part of the blocking. Clerk, for example, blocks throwaway emails at no extra cost. Doorwise also identifies the real signups, sets their credits and follows up with them, in the same decision.
Yes. It learns across customers, so a device that farmed free credits on other apps gets flagged when it reaches yours. That gets stronger as more teams join.
Founders and heads of growth at Seed to Series B SaaS companies with a self-serve free trial or free plan, usually with 1,000 or more signups a month. AI products lose the most to each fake account, so we’re starting with them.
We’re setting the price with our early-access teams. Join the waitlist and you’ll see it before you commit to anything.